Well I think its a perfectly reasonable question. Its a question any beginner pilot might ask (OK TP is not a pilot but so what) and an area often misunderstood by non-heli pilots, and even by pilots like WhatLimits who quotes several items of equipment that are not autopilots (Stick trim, flight directors, FMSs).
What is often misunderstood is that with suitably equipped helicopters, the autopilot is normally engaged some time before takeoff and not disengaged until after landing or perhaps until shutdown, unlike fixed-wing where
the autopilot is only engaged when the pilot wants to take his hands/feet off the controls in flight.
This is because of the inherent instability of a helicopter versus a plank (fixed-wing to you!). The most basic autopilot has SAS (stability augmentation system) whereby the system makes control inputs to resist rates of pitch, roll or yaw, thereby giving a feeling of artificial stability. It could be argued that even this is not an autopilot because it does not allow the aircraft to be flown hands/feet off - the aircraft will still want to fall over, just more slowly than it would without the SAS. When the pilot is flying hands-on, SAS mode is there to make the aircraft more stable. In large helis, if SAS is not working this would be considered a significant failure especially in cloud.
The next level of autopilot (sometimes called ASE - automatic stability equipment) comes into effect when the pilot lets go of the controls. It has attitude retention, ie the aircraft can be trimmed to a desired attitude (in terms of pitch and roll), which it will try to retain, and usually these have some sort of heading hold on the yaw control when bank angle is near zero and/or feet are off the pedals.
Then the pilot can select what are what are called the "upper modes" - such things as pressure altitude hold, radio altitude hold, IAS hold, selected heading hold, coupling to Area Nav (FMS), ILS, VOR etc, and the cleverer ones have altitude acquire where the pilot preselects an altitude and the aircraft will climb or descend to achieve it, and/or a pseudo ILS function which allows ILS-like vertical and lateral guidance using GPS data to a waypoint in the FMS.
Some aircraft may have SAR (Search and Rescue) modes such as predefined search patterns, automatic guidance from the cruise to the hover over a point defined in the FMS either by previously over-flying it, or by moving a marker over it on the radar screen, automatic hovering, including the ability to input a fixed lateral and longitudinal velocity (eg to allow hovering over a drifting ship), ability for rear crew to modify the hover position (they can see under the heli when the pilots can't), and automatic transitioning up from the hover to cruise flight.
Modern autopilots can also include such things as controlling the rotor rpm in the event of engine failure, reducing collective if the pilot demands excessive power etc, and generally are at the heart of digital aircraft systems, and typically duplexed or quadruplexed (ie there are 2 or 4 separate computers to cater for failures).
So definitey not a stupid question!
HC